1. Strictly according to the diagram wiring: 0V(B-)3.7V(B1)7.4V(B2)11.1V(B+),Do not deliberately short circuit.2. After the wire is connected, needs to charge first, then have output.3. When the battery is connected in series with 3 groups ,please ensure that the voltage of each battery is the same. If not the same, please fill in each set of batteries and then use.4. Do not mix the good battery and the battery.5. It will be better the capacity of the battery internal resistance is closer.